For the purposes of illustration, FIG. 6 shows a hand-held grinding machine according to the prior art, specifically an angle grinder 1. The machine comprises an elongated housing with a head region 2, in the lower region of which in the figure a tool mount 3, to which a grinding disc 4 is attached, protrudes outward. In order to protect the user, approximately half of the grinding disc 4 is covered by a protective cover 5. The user holds the angle grinder with a first handle 6 extending laterally away from the head 2 as well as with a second handle 7 formed by a tapered portion of the housing opposite the head 2. The motor for driving the tool mount 3 and the tool attached to it, i.e. the grinding disc 4, are arranged in a central, essentially cylindrical portion of the housing 8. The motor is supplied with power here by means of a power cord 9. Vent openings 10 in the motor housing 8 facilitate the supply of cooling air to the motor.
Electric hand-held tools such as the grinding machine 1 described above are often used on construction sites or at other locations contaminated with dust or themselves generate dust during operation. This dust can enter through the vent openings provided in the housing into the interior of the housing and settle there. Such dust deposits can in particular damage the motor and shorten its service life. In devices according to the prior art, the vent openings are thus sometimes covered with dust filters. While the entry of dust into the interior of the housing can be reduced significantly this way, the dust filters become clogged over a period of operation. Since cleaning or replacement of the dust filters is often difficult or simply forgotten, the motor is no longer cooled sufficiently, which can lead to overheating and motor damage.